Let's see...a criminal who runs for his living, runs from cops, from other bad guys and runs to quickly assalt victims.
A woman who probably never runs if not going in the morning for a quick jogging or a fast pace walk.
What are the chances of out-running an attacker? What is the use of giving him her back and get assalted from behind?
If you have hundres of feet advantage ok run, but since when you realize you are being attack, if not really during the attack, it will be with the attacker basically in front of you...I think suggesting turn your back to him and run is not really wise.